A further 141 patients were assessed for eligibility but excluded (of this group 82 were due to logistical reasons and 42 due to inability to consent)

Methodology

Double-blinded randomised controlled trial with block randomisation to either group DEEP or group STANDARD

Group STANDARD received 0.6mg/kg rocuronium at induction then, if conditions were assessed as poor, a first line intervention of propofol and second line intervention of rocuronium 10mg were given

Group DEEP received 0.6mg/kg rocuronium at induction then and infusion of rocuronium titrated to a post-tetanic count of 0-1 – with same interventions as above if conditions assessed as poor

Neuromuscular monitoring was via “TOF-Watch” at the ulnar nerve

Assessment of surgical conditions was made every half hour and after any intervention via 5-point subjective scale (that 5 surgeons had been trained in pairs to use prior to the study) ranging from 1 (extremely poor) to 5 (optimal)

Average surgical ratings were better in group DEEP at 4.75 vs 4.0 (out of max 5)

Fewer anaesthetic interventions were required in the DEEP group

All patients in group DEEP were reversed with suggamadex vs 14% requirement in group STANDARD

No change in postoperative complications was detected

Strengths

Similar groups with appropriate randomisation and blinding

Demonstrated a statistically significant treatment effect between the two groups using study’s own (albeit non-validated) scale

All patients randomised were accounted for in final analysis

Weaknesses

Large group (82) assessed for eligibility but excluded for ‘logistic reasons’

Subjective nature of scoring system

Inadequately powered for detecting secondary outcomes

It is possible that infusion kinetics titrated to a less deep level of block would produce the same improvement in conditions

The ‘STANDARD’ group arguably does not reflect standard anaesthetic practice – giving only a single dose of NMB, not using NM monitoring, and giving a further dose (after first trialing propofol) only if surgical conditions are poor

Small overall difference in primary outcome (average score of good vs average score approaching optimal) may not justify the significant increase in suggamadex usage